Apparatus, and associated method, for forming a page message including a structure of partial identifiers of differing bit lengths using random or pseudorandom numbers and for using random ATI

ABSTRACT

Apparatus, and an associated method, for facilitating paging of an access terminal operable in a radio communication system. Access-terminal assignment is provided by which to identify an access terminal that is to be page. A first-generated number is detected, such as an access-terminal-originated number. Selection is made as to whether to use the first-generated number. If selection is made not to use the first-generated number, a second number is instead used.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims the priority of provisional patentapplication No. 60/825,214, filed on Sep. 11, 2006, the contents ofwhich are incorporated herein by reference.

The present invention relates generally to a manner by which to page anaccess terminal of a radio communication system to alert the accessterminal of a pending call, or other communication. More particularly,the present invention relates to an apparatus, and an associated method,by which to form a quick page message that includes a structure, formedof partial identities of access terminals that are paged. The bit lengthof one or more of the partial identities is shortened, and one or moreothers have a bit length that is lengthened in an attempt to createpartial identities that are of redundant values. When two or moreidentities are of the same values, duplicate partial identities areremovable from the page message, permitting the bits of the removed,partial identities to be allocated to, e.g., increase lengths of partialidentities remaining in the structure of the page message.

When quick paging is performed through broadcast of a page message, fora given number of pages included in the page message, the structure ofthe page message includes partial identities of lengths best to minimizeoccurrence of false wakeup of an access terminal to which the message isbroadcast. Excessive battery depletion as a result of false wakeup ofthe access terminal is avoided.

BACKGROUND OF THE INVENTION

Advancements in communication technologies have permitted thedevelopment and deployment of new types of communication systems andcommunication services. Cellular telephony, and associated communicationservices available therethrough, are popularly utilized by many,typically providing users with communication mobility and also providesthe capability of communications when the use of wireline communicationsystems would not be practical or possible.

While early-generation, cellular communication systems providedprimarily for voice communications and only limited data communicationservices, newer-generation systems increasingly provide for high-speeddata communication services at variable data communication rates. ACDMA2000, cellular communication system that provides for EV-DO servicesis an exemplary type of new-generation, cellular communication systemthat provides for high-speed data services. Operational details andprotocols defining communications and operational requirements ofdevices of the system are set forth in an operating standardspecification. Various aspects of operation of the CDMA2000 EV-DOcommunication scheme remain to be standardized and certain parts of theexisting standard specification are considered for amendment. Varioussuccessor-generation communication schemes are also undergoingstandardization and yet others are envisioned to be standardized.

For instance, a revision to the standard specification, release B of theCDMA2000 EV-DO specification standard defines a quick paging channel(QPCH) available upon which to broadcast access-terminal pages by anaccess network (AN) to an access terminal (AT). The QPCH was adopted inindustry contributions 3GPP2 C20-20060323-013R1 and 3GPP2C20-20060323-003R1 and published in 3GPP2 document C.S0024-B V1.0.Generally, pages are broadcast by the access network to an accessterminal to alert the access terminal of a pending communication. And byso alerting the access terminal, the access terminal performs actions topermit the effectuation of the communication. Page indications broadcastupon the quick paging channel are broadcast in a manner that facilitatesreduced battery consumption of the access terminal by reducing thebattery consumption of the battery of the access terminal. Increasedbattery longevity is provided, reducing the rate at which a battery ofthe access terminal must be recharged. The access terminal is, as aresult, able to be operated for a greater period of time betweenrechargings or battery replacement. The aforementioned promulgationsprovide for broadcast of a message including page indications upon aphysical logical layer that is monitored by the access terminal. Theaccess terminal monitors the QPCH prior to monitoring the controlchannel to receive regular, control channel MAC (medium access control)messages such as page messages. A quick page message is broadcast uponthe QPCH.

In one configuration, the quick page message contains quick pageindicators. The quick page message includes a number of quick pageindicator slots populated with the quick page indicators that indicatewhether an access terminal is being paged. An exemplary configuration ofa scheme that utilizes page indications is set forth, for instance, inindustry contribution 3GPP2 C20-20060731-033. In this configuration,during operation, a mobile station hashes to a quick page indicatorlocation, i.e., slot, within the quick page message based upon a sessionseed, i.e., a 32-bit pseudorandom number. If the quick page indicator ofthe quick page indicator slot to which the access terminal hashesindicates that the access terminal is not being paged, the accessterminal enters into a sleep state, a reduced-power state, in which theaccess terminal does not remain powered at a level to receive theregular control channel MAC messages. Power savings is particularlysignificant in the event that the control channel MAC messages arelengthy and span multiple control channel frames or capsules.

In another configuration, a partial hash comparison scheme is provided.In the disclosed partial hash comparison scheme, the access networkforms a quick page message in which a portion of an access terminalidentifier (ATI) of an access terminal that is paged is placed in thequick page message. An access terminal that monitors for the delivery ofa quick page message, reads the content of the message and compares thevalues with corresponding values, that is, portions of a hash of theidentifier of that access terminal. If the values do not match, then theaccess terminal enters into a reduced power state, e.g., a sleep state.Contribution C20-20060731-033 shows that partial hashes can also be usedin a partial comparison method to improve battery life; a partial hashof an ATI will be more random than an ATI. Contribution C21-20060906-003and also C21-20060906-004 propose that an AN page an AT on the QuickPaging Channel and regular paging channel, respectively, using apseudorandom variable called a SessionSeed. ContributionC20-20060731-033 had proposed paging with a hash of an ATI. Partialcomparison using a pseudorandom variable will be more random than a hashof an ATI, particularly using the hash function in the 3GPP2specification C.S0024-B v1.0. Partial comparison using the SessionSeedalso provides more random bits than the current hash function inC.S0024-B v1.0. Additionally, U.S. Pat. No. 6,072,987 introduces theidea of partial address comparison to improve battery life. Partialaddress comparison is performed, starting with the LSBs of an address toovercome the problem of an address not being random in all bits.

The QPCH message, as presently-proposed, provides thirty-five pageindication locations, i.e., bits available to be populated with pagingindicators. The aforementioned “partial hash comparison” scheme utilizesthree of the thirty-five page indication locations for identifying thenumber of pages, and the remaining page indication locations areavailable for paging, viz., are available. While the proposed, partialhash comparison scheme reduces the false wakeup probability when pagingload is relatively low, as the paging load increases, the reduction inthe available page indication locations actually increases thepossibility of false wakeup. When more than five access terminals arepaged, partial hash comparison is not used due to this increasedpossibility. Instead, hashing to page indication locations is performed.Additionally, 3GPP2 contribution C22-20060825-008 proposes that an ANassign a paging ATI to the AT. But this contribution fails to propose anATI assignment algorithm for the Access Network.

If a manner could be provided by which to improve the performance of ascheme that utilizes partial comparison pursuant to paging by betterreducing the possibility of false wakeup, improved battery longevity ofthe access terminal would be possible.

It has further been suggested that paging using a SessionSeed is notideal for the reason that the SessionSeed would be used for too manyactivities, viz. the variable would be overloaded. If a further mannercould be provided that does not require use of the SessionSeed, thisproblem would be avoided.

It is in light of this background information related to paging by anaccess network of an access terminal that the significant improvementsof the present invention have evolved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a functional block diagram of a radio communicationsystem in which an embodiment of the present invention is operable.

FIG. 2 illustrates a representation of exemplary structures that areformable pursuant to operation of an embodiment of the presentinvention.

FIG. 3 illustrates a representation, similar to that shown in FIG. 2,but of a representation of other exemplary structures formable pursuantto additional operation of an embodiment of the present invention.

FIG. 4 illustrates a representation for random/pseudorandom ATIassignment pursuant to an embodiment of the present invention.

FIG. 5 illustrates another representation for random/pseudorandom ATIassignment.

FIG. 6 illustrates another representation for random/pseudorandom ATIassignment pursuant to another embodiment of the present invention.

FIG. 7 illustrates another representation for random/pseudorandom ATIassignment pursuant to another embodiment of the present invention.

DETAILED DESCRIPTION

The present invention, accordingly, advantageously provides anapparatus, and an associated method, by which to page an access terminalof a radio communication system to alert the access terminal of apending call, or other communication.

Through operation of an embodiment of the present invention, a manner isprovided by which to form a quick page message that includes a structureformed of partial identities of access terminals that are paged. Thepartial identities are each of selected lengths, selected in mannersthat act to facilitate reduction in the possibility of false wakeup ofan access terminal that monitors delivery of the quick page message.

In one aspect of the present invention, the bit length of one or more ofthe partial identities is shortened and one or more of the others of thepartial identities is lengthened. The selection of the bit-lengthshortening and bit-length lengthening is made better to cause creationof partial identities of identical values, thereby to become redundant.By decreasing the bit length of a partial identity, the likelihood ofits identity with another partial identity of the same length isincreased. And, when redundant partial identities are formed, theredundancy is removed, permitting the bits of the redundant, partialidentity to be allocated to lengthen other partial identities. Suchincrease facilitates reduction in the likelihood of a false wakeup at anaccess terminal that receives the quick page message.

In another aspect of the present invention, a partial identity scheme isutilized in the quick paging procedure. The partial identity comparisonutilizes parts of the identifiers, such as access terminal identifiers(ATIs), pseudorandom or random numbers, or any other numbers amenablefor association with access terminals that are paged. The portion of theidentifier that is included in the quick page message comprises, forinstance, a selected number of the most significant bits, or leastsignificant bits, of the number. The length of each of the partialidentifiers is selected and is dependent upon various factors.

The length of the quick page message is prescribed. For instance, thequick page message is of a thirty-five bit length of which thirty-twobits are available to be populated with a structure including a selectednumber of partial identifiers. The other three bits, e.g., identify thenumber of pages contained in the quick page message. In general, whenthe number of pages increases, the number of bits available in the quickpage message available to identify a particular access terminaldecreases due to the prescribed length of the quick page message. Thatis to say, for example, if thirty-two bits are available in the quickpage message, and only one access terminal is paged, all thirty-two bitsare allocable to identify the access terminal that is paged. However, iftwo access terminals are to be paged, the same thirty-two bits must bedivided so that both of the access terminals can be paged. Analogously,when three access terminals are paged, the available thirty-two bits ofthe quick page message must be divided to permit all three of the accessterminals to be paged, and so forth when there are greater numbers ofaccess terminals that are paged.

In a conventional proposal, the available bits of the quick page messageare divided equally to provide to each of the access terminals that arepaged an equal number of bits in the quick page message when a partialcomparison scheme is used. However, depending upon the number of pages,the thirty-two available bits cannot be divided equally. To maintain theequal distribution of the allocated bits, one or more of the thirty-twobits is unused.

Operation of an embodiment of the present invention both makes betterutilization of all the available bits of the quick page messageavailable to page access terminals and to select a structure includingselection of lengths of partial identifiers of the access terminals thatare to be paged. Selection of the bit lengths of the partial identifiersis made to increase the possibility of occurrence of redundant partialidentifiers that permit the redundancies to be removed out of the quickpage message and the bit locations of the removed, redundant values arethen usable to increase the bit lengths of the partial identifiers ofthe remaining, e.g., non-redundant, partial identifiers.

By reducing the bit-length of a partial identifier, the possibility ofthe shortened, partial identifier being identical with another partialidentifier of the same length increases. By creating such a redundancy,a redundant partial identifier is removable out of the quick pagemessage, and the structure of the quick page message is changed toreallocate the newly-available bits to lengthen the partial identifiersof one or more other partial identifiers of the structure. Differentnumbers of partial bits are used dependent upon the number of partialbits of the partial identifiers of different access terminals match.

In these and other aspects, therefore, an apparatus, and an associatedmethod, is provided for an access network of a communication networkthat generates a first page message on a first paging channel. Adeterminer is configured to determine page values of each pageidentifier set of each page intended to be included in the first pagemessage. A rearranger is configured to rearrange a length of at leastone of the page identifier sets of pages intended to be included in thefirst page message. Rearrangement is made in a manner that facilitatesreduction in a probability parameter.

In these and further aspects, a further apparatus, and an associatedmethod, is provided for an access terminal that monitors a first pagingchannel for delivery of a first paging message. A number-of-pagesdetector is configured to detect how many page identifier sets areincluded in the first page message. A page identifier set value detectoris configured to detect values of each page identifier set detected bythe number-of-pages detector to be included in the first page message.Lengths of the page identifier sets are arranged in a mannerfacilitating reduction of a probability parameter.

Referring first, therefore, to FIG. 1, a radio communication system,shown generally at 10, provides for communications with accessterminals, of which the access terminal 12 is exemplary. Thecommunication system forms a multi-user communication system thattypically includes a large number of access terminals and a plurality ofconcurrent communication dialogs. While only a single access terminal isshown in FIG. 1, additional access terminals, analogous to the accessterminal 12, typically form a portion of the communication system.

Communications are effectuated between an access terminal and a radionetwork 14, formed of fixed network infrastructure elements, such as abase transceiver station (BTS) 16 and a base station controller (BSC)18. The access network encompasses a geographical area within whichcommunications with the access network are possible. That is to say,when an access terminal is positioned within the area encompassed by theaccess network, the access terminal is generally able to communicatewith the access network, and the access network is typically able tocommunicate with the access terminal.

The communication system is operable in general conformity with theoperating protocols and parameters of an appropriate communicationspecification standard. The description set forth herein is exemplary,and the teachings of various embodiments of the present invention areimplementable in any of various types of communication systems.

As previously mentioned, access terminals are alerted, by broadcast of apage message when a communication, initiated at the network, is to beterminated at an access terminal. A quick paging channel (QPCH), oranalogous channel, is defined. Information contained in a quick pagemessage broadcast on the quick paging channel identifies accessterminals that are paged. When an access terminal detects, from thequick page message, that the access terminal is paged, the accessterminal further operates in anticipation of the page and subsequentcommunication. The access terminal, conversely, enters into areduced-power consumption state, e.g., a sleep state, if the accessterminal does not determine that it is being paged. If the accessterminal incorrectly determines that it is being paged, the accessterminal falsely wakes up. And, increased levels of power are consumedby the access terminal, resulting in reduced battery longevity. Theaforementioned partial hash comparison scheme is intended to reduce thelikelihood of false wakeup of the access terminal, but, as presentlyimplemented, provides advantages only when a quick page message pagesfive or fewer access terminals. Additionally, not all of the bits of aquick page message are fully utilized in every paging scenario, and theexisting scheme, for this reason, is less than ideal.

Accordingly, pursuant to an embodiment of the present invention, theaccess network includes apparatus 24, and the access terminal includesapparatus 26, that operate pursuant to quick page message generation andquick page message receipt in manners that reduce the likelihood ofoccurrence of false wakeup relative to an existing partial hashcomparison scheme. The elements of the apparatus 24 and of the apparatus26 are functionally represented, implementable in any desired manner,including, for instance, by algorithms executable by processingcircuitry.

The elements forming the apparatus 24 are implemented at any appropriatelocation of the access network, including, as illustrated, at the BTS 16or BSC 18, or distributed amongst such entities, as well as others.

Here, the apparatus 24 includes a determiner 32, a comparator 34, arearranger 35, a redundant page value remover 36, and a quick pagemessage formatter 38.

The determiner 32 operates to determine, based upon information providedthereto, here represented by way of the lines 42, information associatedwith a quick page message that is to be created for broadcast to accessterminals. The information provided to the determiner includes, forinstance, identifiers that identify the access terminals that are to bepaged. The identifiers comprise multi-bit numbers, for instance, formingthe access terminal identifiers (ATIs) of the access terminals,pseudorandom numbers, or random numbers, or any other values amenablefor identification of an associated access terminal. The determiner, forinstance, determines, based upon the number of pages intended to beincluded in the quick page message, to create partial identifiers of therespective identifiers of the access terminals. Determinations made bythe determiner of the bit lengths of the partial identifiers are, forinstance, conventionally-selected bit lengths. Indications ofdeterminations made by the determiner are provided to the comparator 34and to the rearranger 35. The comparator compares values of the partialidentifiers intended to be included in the quick page message. Suchcomparisons indicate whether any of the partial identifiers areredundant. As a result of comparisons made by the comparator, theredundant page remover 36 removes the redundant partial identifiers. Aloop back to the determiner, here represented by way of the path 44,permits reconfiguration of the partial identifiers subsequent to removalof a redundant partial identifier.

Here further, the rearranger 35 is operable. The rearranger is operablefurther to rearrange the bit lengths of the partial identifiers that aredetermined by the determiner to be includable in a quick page messageintended to be broadcast.

In first exemplary operation of an embodiment of the present invention,the determinations made by the determiner 32 are first provided to therearranger 35, and the rearranger 35 rearranges the bit lengths of oneor more of the partial identifiers. A bit-length of at least one of thepartial identifiers is reduced, permitting, if desired, lengthening ofthe bit length of one or more others of the partial identifiers. Therearrangement made by the rearranger, such as by shortening the bitlength of a partial identifier, increases the possibility that anotherpartial identifier of corresponding length shall be of the same valuesand thereby be redundant thereto. That is to say, therefore, therearranger 35 operates to form partial identifiers in manners toincrease the possibility of formation of redundant partial identifiers.Redundant partial identifiers need not be included in a quick pagemessage and are deletable by the redundant page remover 36. In thisexemplary operation, determinations made by the determiner 32 areprovided to the rearranger 35. The rearranger 35 rearranges the bitlengths of one or more partial identifiers. Once rearranged, the partialidentifiers are compared by the comparator 34, and redundancies areremoved by the redundant page remover 36.

In alternate operation, rearrangement is performed by the rearranger 35subsequent to a first pass of determined values determined by thedeterminer 32 and compared by the comparator 34. Or, if desired,operation need not include operation of the rearranger although,generally, the advantages provided by the rearranger in increasing thelikelihood of formation of redundant, partial identifiers is not thenprovided.

Upon completion of rearrangement, comparison, redundant page removal,and reallocation, if elected, of the available bits, indications areprovided to the quick page message formatter 38. The quick page messageformatter 38 formats a quick page message to include the partialidentifiers that shall be included in the quick page message,subsequently to be broadcast by the access network.

Through removal of redundant, partial identifiers, better use is made ofthe limited bit-length of the quick page message. And, through operationof the rearranger 35, the likelihood of a redundancy of a partialidentifier, permitting its removal, is increased. When such operationreduces the likelihood of false wakeup of an access terminal, suchoperation facilitates communication activities in the communicationnetwork.

FIG. 2 illustrates an exemplary representation of operation ofrearrangement, such as that performed by the rearranger 35 shown inFIG. 1. Here, the structure, represented at 62 of a quick page message,such as that determined by the determiner 32 shown in FIG. 1, includesfour partial identifiers, each of eight-bit lengths. Rearrangementperformed by the rearranger creates any of various alternate structuresof which structures 62-1, 62-2, and 62-3 are shown. The structure 62-1is of bit lengths of nine-bit, eight-bit, eight-bit, and seven-bitlengths, respectively. The structure 62-2 includes partial identifiersof bit-lengths of nine bits, nine bits, eight bits, and six bits,respectively. And, the structure 62-3 is formed of partial identifiersof nine-bit, nine-bit, nine-bit, and five-bit lengths, respectively.

FIG. 3 illustrates other exemplary structures formable pursuant tooperation of an embodiment of the present invention. Here, a structureinitially formed includes partial identifiers of five access terminals.Initially, each of the partial identifiers is of a six-bit length.Rearrangement operations form any of various alternate structures, ofwhich three alternate structures, designated as 72-1, 72-2, and 72-3 areshown in the figure. The structure 72-1 includes partial identifiers ofseven-bit, seven-bit, seven-bit, six-bit, and five-bit lengths,respectively. The structure 72-2 is formed of partial identifiers ofseven-bit, seven-bit, seven-bit, seven-bit, and four-bit lengths,respectively. And, the structure 72-3 is formed of partial identifiersof eight-bit, seven-bit, seven-bit, seven-bit, and three-bit lengths,respectively.

Referring back to FIG. 1 again, transceiver elements of the basetransceiver station 16 cause broadcast of quick page messages that havebeen formatted by the quick page message formatter. The messages arebroadcast upon a radio air interface, represented in FIG. 1 by the arrow63. The messages are delivered to access terminals, such as the accessterminal 12, within reception range of the broadcast messages. Theaccess terminal 12 includes transceiver circuitry, here represented by areceive part 64 and a transmit part 66. The receive part 64 operates toreceive signals sent thereto, such as the quick page messages broadcastby the access network. And, certain of the detected signals are providedto the apparatus 26 embodied at the access terminal. Of significancehere are detections of the quick page message broadcast by the accessnetwork.

The apparatus 26 includes a number-of-pages detector 73 and a pageidentifier set value detector 74. The elements are functionallyrepresented, also implementable in any desired manner, includingalgorithms executable by processing circuitry. The detector 73 detectsan indication in the quick page message of the number of pages that areincluded in the received quick page message. The number of pages areindicated in, e.g., and as noted above, a three-bit segment of the quickpage message. Detection of such indication is used by the pageidentifier set value detector 74 in the detection of the page identifiersets, thereby to determine whether the access terminal is paged.Additional operation at the access terminal determines, in response tothe number of pages detected by the page detector of the page valuelengths of the page identifier set or sets contained in the quick pagemessage. In the event that the detector detects the access terminal notto be paged, an indication is provided to an access terminal (AT) statecontroller 84 to cause the access terminal to be placed in areduced-power state, e.g., a sleep mode. If a page is detected,conversely, an indication is provided to the state controller and thecontroller causes the state of the access terminal to permit its furtheroperation with respect to paging and further communication.

The false wakeup probability at an access terminal is governed by theequation:1−[1−“½^(n)”]

Wherein:

n identifies the number, i.e., bit length, of partial identifiers.

Through operation of an embodiment of the present invention, newstructures are provided that, when used, reduce the likelihood ofoccurrence of false wakeup. FIGS. 2 and 3 illustrate various of the newstructures when four and five identifiers are to be paged within a quickpage message. During operation of an embodiment of the presentinvention, the number of bits for one of the partial identifiers islowered in order to give a higher probability of a match of, viz.,redundancy with, another partial identifier. In an example of five pageswithin a quick page message, there is a fifty-one percent possibility ofoccurrence of at least two five-bit partial identifiers being a match.Analogously, there is a twenty-eight percent probability of match ofsix-bit partial identifiers, a fifteen percent probability of redundancyof at least two seven-bit partial identifiers, and an eight percentprobability of redundancy of at least two eight-bit partial identifiers.Structures are used if the likelihood of false wakeup for the structureis less than the likelihood of false wakeup when a hashing to individualpage indication locations and use of single-bit identifiers are used.

The false wakeup probability for the structure 62-1 shown in FIG. 2 isgoverned by the following equation:

$1 - {\left( {1 - \frac{1}{2^{9}}} \right)\left( {1 - \frac{1}{2^{8}}} \right)^{2}\left( {1 - \frac{1}{2^{7}}} \right)}$

The false wakeup probability for the structure 62-2 shown in FIG. 2 is:

$1 - {\left( {1 - \frac{1}{2^{9}}} \right)^{2}\left( {1 - \frac{1}{2^{8}}} \right)\left( {1 - \frac{1}{2^{6}}} \right)}$

The false wakeup probability for the structure 62-3 shown in FIG. 2 is:

$1 - {\left( {1 - \frac{1}{2^{9}}} \right)^{3}\left( {1 - \frac{1}{2^{5}}} \right)}$

The structure that exhibits the lowest false wakeup probability and thatgenerates a partial identifier that can be eliminated, if any, is thestructure used by the access network. The overall false wakeupprobability for a number of pages is determinable by summing theproducts of the various false wakeup probabilities for the new structureand the percentage of page combinations that would use them togetherwith the product of the false wakeup probability of a page indicationmethod for the number of pages and the percentage of page combinationswhere matches are unable to be made.

In a further embodiment, the access terminal is permitted immediately torespond to a quick page message without receiving the regular pagemessage, but only if doing so would result in an acceptably low falsepage response probability. For example, suppose that the QPCH structuredescribed in contribution 3GPP2 document C21-20060906-004 were used. Theprobability of a “match” on the quick page message for the case of onepage is

$\frac{1}{2^{29}}$or 1.86×10⁻⁹. The probability of a “match” on the quick page message forthe case of two pages is

$1 - {\left( {1 - \frac{1}{2^{15}}} \right)\left( {1 - \frac{1}{2^{15}}} \right)}$or 6.10×10⁻⁵. The probability of a “match” on the quick page message forthe case of three pages is about

$1 - {\left( {1 - \frac{1}{2^{11}}} \right)\left( {1 - \frac{1}{2^{11}}} \right)\left( {1 - \frac{1}{2^{11}}} \right)}$or 0.00146. 0.00146 may not be an acceptable probability of a false pagematch, but 1.86×10⁻⁹ and 6.10×10⁻⁵ would be both acceptably low for anumber of false page matches. So if the false page response probabilitywould be reasonably low after only receiving a quick page message andperforming partial identity comparison on the quick page messagecontents, the AT could perform a page response immediately afterdetecting a partial identity match in the quick page message only. Inthis case the AT would be allowed to perform a page response after apartial identity match for either one or two pages. For three pages ormore, however, the AT would wake up for the regular page message andperform partial identity comparison on the regular page message if itdetected a partial identity match in the quick page message and onlyperform the page response if it detected a partial identity match in theregular page message.

The number of pages that would trigger a page response using the quickpage message alone would depend upon the size of the quick page message.The AN could control the threshold at which ATs are allowed to performpage responses using the quick page message only by means of a parametersent to ATs. For example, the AN could send a value of number of pages(i.e. send the value 2 to allow page responses on a partial identitymatch if there are two or fewer pages in the Quick Page Message).Alternately, the AN could send a value such as a match probability (i.e.broadcast 10⁻⁵ if ATs are allowed to send page response after receivingquick pages only if the probability of a false match after receiving thequick page message is less than 10⁻⁵).

According to this further embodiment, page responses with reducedlatency are enabled by allowing ATs to perform page responses afterreceiving the quick page message only if the probability of a false pageresponse would be acceptably low and otherwise receiving the regularpage message.

The disclosure aims to improve battery life by introducing a method forpartial identity comparison with random or pseudorandom bits in pagemessages.

Addresses are transmitted starting with the least significant bit andcontinuing with more significant bits. If the address is long, it couldpotentially get to a less random part of the address and the techniquewould be less effective. Contribution C20-2006731-033 suggests thatpartial hashes be used in partial comparison method. The hashes would behashes of an address. The address that the hash is based on may not becompletely random, so this may still not produce the best partialidentities for partial identity comparison. If a hash is not completelyrandom, it could result in an increase in the false wakeup probability.Furthermore, the hashing is an extra step that would be nice to avoid.The invention solves the problem by performing partial identitycomparison using a random or pseudorandom variable (such as SessionSeed)that is known to both the AN (access network) and the AT (accessterminal). Most significant bits of the SessionSeed could be used aspartial identities in page messages, for example.

FIG. 4 shows a method for random/pseudorandom ATI assignment where therandom/pseudorandom number is generated at the AT. First the ATgenerates a random or pseudorandom number. The AT then puts it in asignaling message and transmits it to the AN. One option would be to usethe SessionSeed field as in the current 3GPP2 C.S0024-B v1.0specification; alternately, another field could be used. The AN thenstores the number as the AT's ATI. The AN may then optionally send amessage to the AT including the number and assigning it to the AT as theATI. The AT upon receiving this message will store the number as itsATI. The AN will then perform quick paging and paging to that AT usingthe ATI. The AT will then use the ATI for paging and quick pagingpartial comparison techniques.

FIG. 5 shows a method for random/pseudorandom ATI assignment where therandom/pseudorandom number is generated in the AN. First the AT sendsthe AN a message using an address other than the ATI. The AN thengenerates a random or pseudorandom number and stores it as the AT's ATI.The AN then sends a message to the AT including the number and assigningit to the AT as the ATI. Upon receiving the message, the AT will storethe pseudorandom number as the ATI. The AN will then perform quickpaging and paging to that AT using the ATI. The AT will then use the ATIfor paging and quick paging partial comparison techniques.

This paragraph describes a way that the proposed invention could be usedin conjunction with a number of messages and procedures from theexisting C.S0024-B standard. A random ATI value for UATI-based ATIrecord is created and used in paging. The partial bits of the random ATIare then used in partial comparison on the quick paging channel and/orthe regular paging channel. The ATI that will be used for partialcomparison for paging and quick paging will be set to a random orpseudorandom number. The AN could compute the number itself using apseudorandom number generator or using some random physical input; theAN would then send the assigned paging ATI to the AT in a signalingmessage. Alternately the AT could compute the number itself using apseudorandom number generator or using some random physical input. TheAT could then send this message to the AN in a signaling message. Onesuch example is Random ATI (RATI) that AT uses in initial UATI Requestmessage. The RATI is effectively the pseudorandom SessionSeed computedby AT and AN can set the least significant 24 bits of UATI to the leastsignificant 24 bits of RATI sent by the AT; alternately, the AT couldsend another random or pseudorandom number to the AN in addition to theSessionSeed. Yet another alternative is to create a random value basedon SessionSeed/RATI used by AT and UATI assigned by AN.

The AN keeps track of the hashes that will be generated by ATs whose ATIit assigned. When generating a new ATI it will assign in such a way thatthe hashes on the ATIs will be distributed uniformly.

The embodiments of FIGS. 4 and 5, therefore, solve the problemconcerning excessive use of the SessionSeed. Instead, the ATI isassigned to be a random or pseudorandom number and performing quickpaging and paging with the random ATI and using the random ATI forpartial comparison. The least significant and most significant bits ofthe ATI can then be used for partial comparison.

FIG. 6 shows a method for random/pseudorandom ATI assignment where therandom/pseudorandom number is generated at the AT. First the ATgenerates a random or pseudorandom number. The AT then puts it in asignaling message and transmits it to the AN (step a). One option wouldbe to use the SessionSeed field as in the current 3GPP2 C.S0024-B v1.0specification; alternately, another field could be used. The AN thenchecks to see if another AT has already been assigned the receivedrandom/pseudorandom number. If another AT has already been assigned thatnumber as its ATI, then the AN will send a reject message to the AT(step b); otherwise, the AT skips to step d where it stores the numberas the AT's ATI and optionally sends a message to the AT including thenumber and assigning it to the AT as the ATI. Upon receiving the rejectmessage (step b), the AT will generate a new random or pseudorandomnumber and puts it in a signaling message and transmitting it to the AT(step c). Although not shown, the AN would again check to see if thenumber is assigned to another AT and steps b and c would be repeateduntil a unique ATI is generated. The AT upon receiving the optionalmessage at step d will store the number as its ATI. The AN will thenperform quick paging and paging to that AT using the ATI. The AT willthen use the ATI for paging and quick paging partial comparisontechniques.

FIG. 7 shows a method for random/pseudorandom ATI assignment where therandom/pseudorandom number is generated in the AN. First the AT sendsthe AN a message using an address other than the ATI. The AN thengenerates a random or pseudorandom number and stores it as the AT's ATI.The AN will check to see if the random or pseudorandom number is alreadyassigned as another AT's ATI and if so, will repeat the generation ofthe random or pseudorandom number until a unique ATI has beendetermined. The AN then sends a message to the AT including the numberand assigning it to the AT as the ATI. Upon receiving the message, theAT will store the pseudorandom number as the ATI. The AN will thenperform quick paging and paging to that AT using the ATI. The AT willthen use the ATI for paging and quick paging partial comparisontechniques.

Alternately, steps of FIG. 6 and of FIG. 7 are combined. For example,suppose that the AT generates the random/pseudorandom number and sendsit to the AN and the AN determines that it is already in use; the ANcould then generate a unique random or pseudorandom number as describedwith respect to FIG. 7 and send it in a signaling message to the AT,overriding the number sent by the AT.

Presently preferred embodiments of the invention and many of itsimprovements and advantages have been described with a degree ofparticularity. The description is of preferred examples of implementingthe invention, and the description of preferred examples is notnecessarily intended to limit the scope of the invention. The scope ofthe invention is defined by the following claims.

1. A method for facilitating paging of an access terminal, said methodcomprising: detecting a quick paging message including detecting a firstpartial identity that identifies the access terminal among a quantity ofpartial identities identifying access terminals; and responding to thedetected quick paging message when a probability of false partialidentity detection based on the quantity of partial identities includedin the quick paging message is less than a probability threshold.
 2. Themethod of claim 1 wherein the first partial identity comprises part of arandom or pseudorandom number.
 3. The method of claim 2 wherein thefirst partial identity comprises part of a session seed.
 4. The methodof claim 1 wherein responding comprises responding with a page responsemessage.
 5. The method of claim 1 wherein the probability threshold isbased upon a value received from the access network.
 6. The method ofclaim 1 wherein responding comprises waking up to detect a regularpaging message.
 7. An apparatus for facilitating paging of an accessterminal, said apparatus comprising: a detector configured to detect aquick paging message including detecting a first partial identity thatidentifies the access terminal among a quantity of partial identitiesidentifying access terminals; and a page responder configured to respondto the detection of the quick paging message when a probability of falsepartial identity detection based on the quantity of partial identitiesincluded in the quick paging message is less than a probabilitythreshold.
 8. The apparatus of claim 7 wherein the first partialidentity comprises part of a random or pseudorandom number.
 9. Theapparatus of claim 8 wherein the first partial identity comprises partof a session seed.
 10. The apparatus of claim 7 wherein said pageresponder is configured to respond with a page response message.
 11. Theapparatus of claim 7 wherein the probability threshold is based upon avalue received from the access network.
 12. The apparatus of claim 7wherein said page responder is configured to cause access terminal towake up to detect a regular paging message.
 13. A method forfacilitating access terminal paging, said method comprising: sending aquick paging message on a quick paging channel, the quick paging messageincluding a first access terminal partial identity among a quantity ofpartial identities identifying access terminals, the first accessterminal partial identity identifying a first access terminal; andreceiving a page response message from the first access terminal when aprobability of false first access terminal identification based on thequantity of partial identities included in the quick paging message isless than a probability threshold.
 14. The method of claim 13 whereinthe first access terminal partial identity comprises part of a random orpseudorandom number.
 15. The method of claim 14 wherein the first accessterminal partial identity comprises part of a session seed.
 16. Themethod of claim 13 wherein said sending further comprises sending theprobability threshold.
 17. An apparatus for facilitating access terminalpaging, said apparatus comprising: an access terminal paging messagesender configured to send a quick paging message on a quick pagingchannel, the quick paging message including a first access terminalpartial identity among a quantity of partial identities identifyingaccess terminals, the first access terminal partial identity identifyinga first access terminal; and a receiver configured to receive a pageresponse message from the first access terminal when a probability offalse first access terminal identification based on the quantity ofpartial identities included in the quick paging message is less than aprobability threshold.
 18. The apparatus of claim 17 wherein the firstaccess terminal partial identity comprises part of a random orpseudorandom number.
 19. The apparatus of claim 18 wherein the firstaccess terminal partial identity comprises part of a session seed. 20.The apparatus of claim 17 wherein said access terminal paging messagesender further comprises a false first access terminal identificationprobability threshold identifying signal sender configured to send theprobability threshold.